In a 5th Generation (5G) standard alternative, based on an existing orthogonal frequency division multiplexing (OFDM) system signal structure, OFDM symbols with different parameters are used in different carrier bands. For example, with an increase of a carrier frequency, a larger subcarrier spacing (or a larger length) and a shorter symbol period are used in the OFDM symbols. In a same transmission time interval (TTI), frequency resources are used in symbols with different subcarrier spacings in a frequency division manner. For example, symbols with subcarrier spacings of 15 KHz and 30 KHz on a frequency band are used for multiplexing of the frequency band.
Because orthogonality between signals cannot be maintained in OFDM symbols with different subcarrier spacings in a same time period, extremely high interference is generated between the symbols with the different subcarrier spacings. Currently, there is no effective method for reducing interference between the symbols with the different subcarrier spacings.